[vsnet-grb-info 3892] GRB 061006: astrometry-corrected XRT position

[GCN Circulars]

TITLE:   GCN CIRCULAR
NUMBER:  5723
SUBJECT: GRB 061006: astrometry-corrected XRT position
DATE:    06/10/09 14:57:28 GMT
FROM:    Eleonora Troja at INAF-IASFPA  <nora at ifc.inaf.it>

E. Troja (U.Leicester,INAF/IASFPa), K. L. Page (U.Leicester), N. Gehrels 
(NASA/GSFC) and D. N. Burrows (PSU) report on behalf of the Swift XRT team:

Using the first 22 ks of XRT PC observations we detected 6 serendipitous X-ray 
sources with S/N>3 in the field of view of GRB 061006. 
Comparing the X-ray centroids to positions of nearby infrared sources, listed 
in the 2MASS catalogue, we noted that a systematic offset is present. We then 
improved the XRT position considering three infrared/X-ray associations and 
we obtained the new X-ray afterglow position:

RA(J2000)= 07h 24m 07.33s
Dec(J2000)= -79d 11' 55.77''

with a shift of Delta RA=2.73 arcsec and Delta Dec=-1.03 arcsec with respect 
to the previous one, reported in GCN Circ. 5703. The corresponding error 
radius is 2.2 arcsec (90% containment).
This new position lies 1.1 arcsec from the optical afterglow candidate 
proposed by Malesani et al. (GCN Circ. 5718).

This circular is an official product of the Swift-XRT team.